Novobiocin is an antibiotic useful in the treatment of staphylococcal injections and in urinary tract infections caused by certain strains of Proteus. It shows no cross resistance with penicillin and is active against penicillin-resistant strains of Staphyloccoccus aureus. Novobiocin is produced through fermentation by streptomycetes. The methods for production, recovery and purification of novobiocin are described in U.S. Pat. No. 3,049,534.
Dihydronovobiocin is an antibiotic prepared by hydrogenating novobiocin according to the procedures disclosed in U.S. Pat. No. 3,175,944.
As with any antibiotic it is always highly advantageous to prepare derivatives or analogs since these often lead to new antibiotics with increased potency, fewer and less severe side effects, and/or a different spectrum of antibiotic activity. In 1972 U.S. Pat. No. 3,652,536 disclosed an enzymatic process for cleaving novobiocin to produce novenamine. U.S. Pat. No. 3,890,297 disclosed a selective process for N-acylation of novenamine which produces novobiocin analogs which have antibacterial activity.
The following patents disclose modifications of novobiocin: U.S. Pat. Nos. 2,925,411; 2,938,899; 2,945,064; 3,049,550; and 3,445,455; British Pat. Nos. 856,816 and 997,179; and German Pat. Nos. 1,088,982 and 1,076,144.
However none of the above relate to modification of the isopentenyl side chain on the benzamide ring. To our knowledge only the combined process of U.S. Pat. Nos. 3,652,536 and 3,890,297 disclosed a useful method for producing such analogs until the present invention.